Tank, battery cell, battery, and electrical device

ABSTRACT

A tank includes a plurality of independent accommodation cavities. Each of the accommodation cavities includes a corresponding fragile structure, and the fragile structures possess different packaging strengths.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of International Application No.PCT/CN2021/114640, filed on Aug. 26, 2021, the entire content of whichis incorporated herein by reference.

TECHNICAL FIELD

This application relates to the field of batteries, and in particular,to a tank, a battery cell, a battery, and an electrical device.

BACKGROUND

Energy conservation and emission reduction is key to sustainabledevelopment of the automobile industry. Electric vehicles have become animportant part of the sustainable development of the automobile industryby virtue of energy saving and environmental friendliness. Batterytechnology is crucial to development of electric vehicles.

During research, the inventor of this application finds that, with theaging of a cell core and the increase of charge-and-discharge cycles,problems such as electrolyte shortage may occur in an existing batteryduring the cycles.

SUMMARY

Embodiments of this application provide a tank, a battery cell, abattery, and an electrical device to enhance battery safety.

According to a first aspect, an embodiment of this application disclosesa tank. A plurality of independent accommodation cavities are arrangedin the tank. Each of the accommodation cavities includes a correspondingfragile structure. Each fragile structure possesses a differentpackaging strength.

This embodiment of this application implements the function of storingdifferent types of filling substances by using a single tank. Thedifferent filling substances stored in the accommodation cavities in thetank can be released stepwise in response to different externalpressures. Therefore, the cell core at different stages can be refilledwith different dosages of electrolyte or different types of desiredsubstances depending on the internal pressure of the battery cell,thereby improving pertinency of refilling the cell core with desiredsubstances.

In some embodiments, one or more sub-tanks are arranged inside the tank.The tank and the sub-tanks are nested with each other to formindependent accommodation cavities. Packaging strengths of thecorresponding fragile structures of the accommodation cavities increaseprogressively from outward to inward.

The multi-layer nested parent-child tank disclosed in this embodiment ofthis application is simple in structure and implements the function ofstoring different types of filling substances by using a single tank.The different filling substances stored in the accommodation cavities inthe tank can be released stepwise in response to different externalpressures.

In some embodiments, a membrane is arranged in the tank. The membrane isconfigured to partition an interior of the tank into a plurality ofindependent accommodation cavities. The fragile structure is arranged ata position located on a surface of the tank and corresponding to eachaccommodation cavity. Each fragile structure possesses a differentpackaging strength.

The twin tank structure disclosed in this embodiment of this applicationis simple in structure and implements the function of storing differenttypes of filling substances by using a single tank. The differentfilling substances stored in the accommodation cavities in the tank canbe released stepwise.

According to a second aspect, an embodiment of this applicationdiscloses a battery cell, including: a housing; a cell core,accommodated in the housing; and the tank disclosed in the foregoingembodiment, where the tank is accommodated in the housing, and isarranged corresponding to a sidewall of the cell core.

This embodiment of this application implements the function of storingdifferent types of filling substances by using a single tank. Thedifferent filling substances stored in the accommodation cavities in thetank can be released stepwise in response to different externalpressures, thereby improving pertinency of refilling the cell core withthe desired substances. Moreover, with the twin tank and theparent-child tank arranged compositely inside the battery cell, the cellcore can be refilled with substances precisely and meticulously.

In some embodiments, the fragile structure is arranged corresponding tothe sidewall of the cell core.

In this embodiment of this application, the filling substance cancontact the sidewall of the cell core first, thereby improving theeffect of infiltration.

In some embodiments, a plurality of cell cores are included. The tank isarranged between each cell core and a sidewall of the housing, and/orthe tank is arranged between adjacent cell cores.

To improve the effect of infiltration, this embodiment of thisapplication arranges a tank structure between different cell cores. Whenthe gas pressure in the battery cell is excessive, or the cell coreexpands during use, in a case that the expansion force is greater than apressure threshold tolerable by the fragile structure of the tank, thetank arranged between the cell cores is ruptured, and the overflowingsubstance directly contacts the cell core, so that the cell core canabsorb the desired substance more efficiently.

In some embodiments, the tank includes a plurality of fragilestructures. The plurality of fragile structures are arrangedcorresponding to sidewalls of the cell core respectively.

In this embodiment of this application, by arranging a plurality offragile structures corresponding to the sidewalls of the cell corerespectively, the tank can release the filling substance from theplurality of fragile structures simultaneously. A plurality of parts ofthe cell core can contact the filling substance simultaneously, therebyimproving the effect of infiltration for the cell core, and making thecell core absorb the desired filling substance more efficiently.

In some embodiments, an explosion-proof valve is arranged on thehousing, and the tank is arranged opposite to the explosion-proof valve.

In this embodiment of this application, by arranging the tank oppositeto the explosion-proof valve, the filling substance stored in the tankcan be released more efficiently.

In some embodiments, each fragile structure possesses a differentpackaging thickness.

In this embodiment of this application, the corresponding fragilestructure of each accommodation cavity possesses a different packagingstrength. In this way, among the corresponding fragile structures of theaccommodation cavities under the action of the gas pressure in thebattery cell, the filling substance in the accommodation cavitycorresponding to the fragile structure with the lowest packagingstrength is released first. The filling substances in the accommodationcavities corresponding to the fragile structures with relatively highpackaging strengths are released stepwise when the gas pressure in thebattery cell increases gradually.

In some embodiments, packaging strengths of the fragile structureschange stepwise.

In this embodiment of this application, in view of the characteristicsof the internal pressure of the cell core and the substances required bythe cell core in different pressure stages, the packaging strengths ofthe corresponding fragile structures of the accommodation cavities areset to change stepwise to gradually release the substances required bythe cell core.

In some embodiments, each accommodation cavity stores a differentsubstance.

In this embodiment of this application, different substances are storedin different accommodation cavities and available for refilling the cellcore, thereby achieving the purposes such as improving the lifespan ofthe cell core and the safety of the cell core.

In some embodiments, the accommodation cavities store a flame retardant,a gas absorbent, a lithium supplementing agent, and an electrolyticsolution respectively in descending order of the packaging strength ofthe fragile structure.

In this embodiment of this application, the cell core is provided withvarious desired substances more pertinently, thereby achieving thepurposes such as improving the lifespan of the cell core and the safetyof the cell core.

According to a third aspect, an embodiment of this application disclosesa battery cell, including: a housing; a cell core, accommodated in thehousing; and a plurality of tanks, accommodated in the housing, andarranged corresponding to sidewalls of the cell core respectively, wherea fragile structure is arranged on a surface of each of the tanks, andthe fragile structure of each tank possesses a different packagingstrength.

In this embodiment of this application, a plurality of discrete tankswith fragile structures of different packaging strengths are arranged inthe battery cell, so that different discrete tanks can release differentfilling substances stepwise in sequence under different pressures.

In some embodiments, the fragile structure is arranged corresponding tothe sidewall of the cell core.

In this embodiment of this application, the filling substance cancontact the sidewall of the cell core first, thereby improving theeffect of infiltration.

In some embodiments, a plurality of cell cores are included.

The tank is arranged between each cell core and a sidewall of thehousing, and/or the tank is arranged between adjacent cell cores.

To improve the effect of infiltration, this embodiment of thisapplication arranges a tank structure between different cell cores. Whenthe gas pressure in the battery cell is excessive, or the cell coreexpands during use, in a case that the expansion force is greater than apressure threshold tolerable by the fragile structure of the tank, thetank arranged between the cell cores is ruptured, and the overflowingsubstance directly contacts the cell core, so that the cell core canabsorb the desired substance more efficiently.

In some embodiments, the tank includes a plurality of fragilestructures. The plurality of fragile structures are arrangedcorresponding to sidewalls of the cell core respectively.

In this embodiment of this application, by arranging a plurality offragile structures corresponding to the sidewalls of the cell corerespectively, the tank can release the filling substance from theplurality of fragile structures simultaneously. A plurality of parts ofthe cell core can contact the filling substance simultaneously, therebyimproving the effect of infiltration for the cell core, and making thecell core absorb the desired filling substance more efficiently.

In some embodiments, the fragile structure of each tank possesses adifferent packaging thickness.

In this embodiment of this application, the corresponding fragilestructure of each accommodation cavity possesses a different packagingstrength. In this way, among the corresponding fragile structures of theaccommodation cavities under the action of the gas pressure in thebattery cell, the filling substance in the accommodation cavitycorresponding to the fragile structure with the lowest packagingstrength is released first. The filling substances in the accommodationcavities corresponding to the fragile structures with relatively highpackaging strengths are released stepwise when the gas pressure in thebattery cell increases gradually.

In some embodiments, packaging strengths of the fragile structures ofthe tanks change stepwise.

In this embodiment of this application, in view of the characteristicsof the internal pressure of the cell core and the substances required bythe cell core in different pressure stages, the packaging strengths ofthe corresponding fragile structures of the accommodation cavities areset to change stepwise to gradually release the substances required bythe cell core.

According to a fourth aspect, an embodiment of this applicationdiscloses a battery, including the battery cell according to theforegoing embodiment.

According to a fifth aspect, an embodiment of this application disclosesan electrical device. The electrical device includes the batterydisclosed in the foregoing embodiment, and the battery is configured toprovide electrical energy.

BRIEF DESCRIPTION OF DRAWINGS

The drawings described herein are intended to enable a furtherunderstanding of this application, and constitute a part of thisapplication. The exemplary embodiments of this application and thedescription thereof are intended to explain this application but not toconstitute any undue limitation on this application. In the drawings:

FIG. 1 is a schematic structural diagram of a vehicle according to anembodiment of this application;

FIG. 2 is a schematic structural exploded view of a battery according toan embodiment of this application;

FIG. 3 is a schematic structural diagram of a battery cell according toan embodiment of this application;

FIG. 4 is a schematic structural diagram of a parent-child tankaccording to an embodiment of this application;

FIG. 5 is a schematic diagram of a parent-child tank filled withdifferent substances according to an embodiment of this application;

FIG. 6 is a schematic structural diagram of a twin tank according to anembodiment of this application;

FIG. 7 is a schematic diagram of a twin tank filled with differentsubstances according to an embodiment of this application;

FIG. 8 is a schematic structural diagram of a battery cell according toan embodiment of this application;

FIG. 9 is a schematic structural diagram of another battery cellaccording to an embodiment of this application;

FIG. 10 is a schematic structural diagram of a battery cell equippedwith mixed types of tanks according to an embodiment of thisapplication;

FIG. 11 is a schematic structural diagram of a battery cell with aplurality of cell cores according to an embodiment of this application;

FIG. 12 is a schematic structural diagram of a parent-child tank with aplurality of fragile structures according to an embodiment of thisapplication;

FIG. 13 is a schematic structural diagram of a twin tank with aplurality of fragile structures according to an embodiment of thisapplication;

FIG. 14 is a schematic structural diagram of a battery cell equippedwith a plurality of discrete tanks according to an embodiment of thisapplication;

FIG. 15 is a schematic structural diagram of a discrete tank accordingto an embodiment of this application;

FIG. 16 is a schematic diagram of a fragile structure of a discrete tankaccording to an embodiment of this application; and

FIG. 17 is a schematic structural diagram of a discrete tank with aplurality of fragile structures according to an embodiment of thisapplication.

Reference Numerals:

vehicle 1000, battery 100, box 10, upper box 11, lower box 12,controller 200, motor 300;

battery cell 20, housing 210, electrode 220, explosion-proof valve 230,cell core 240;

discrete tank 40, accommodation cavity 410, tank wall 411, fragilestructure 412; first discrete tank 401, first tank wall 411, firstfragile structure 414; second discrete tank 402, second tank wall 421,second fragile structure 422; third discrete tank 403, fourth discretetank 404;

parent-child tank 50, first parent-child tank 501, second parent-childtank 502, third parent-child tank 503, fourth parent-child tank 504,first accommodation cavity 510, first tank wall 511, first fragilestructure (512, 515), first filling substance 513, second accommodationcavity 520, second tank wall 521, second fragile structure (522, 525),second filling substance 523, third accommodation cavity 530, third tankwall 531, third fragile structure (532, 535), third filling substance533;

twin tank 60, first twin tank 601, second twin tank 602, third twin tank603, fourth twin tank 604, first accommodation cavity 610, first tankwall 611, first fragile structure (612, 615), first filling substance613, first membrane 614, second accommodation cavity 620, second tankwall 621, second fragile structure (622, 625), second filling substance623, second membrane 624, third accommodation cavity 630, third tankwall 631, third fragile structure (632, 635), third filling substance633.

DETAILED DESCRIPTION OF EMBODIMENTS

To make the objectives, technical solutions, and advantages of theembodiments of this application clearer, the following gives a cleardescription of the technical solutions in the embodiments of thisapplication with reference to the drawings in the embodiments of thisapplication. Evidently, the described embodiments are merely a part ofbut not all of the embodiments of this application. All otherembodiments derived by a person of ordinary skill in the art based onthe embodiments of this application without making any creative effortsfall within the protection scope of this application.

Unless otherwise defined, all technical and scientific terms used hereinhave the same meanings as usually understood by a person skilled in thetechnical field of this application. The terms used in the specificationof this application are merely intended for describing specificembodiments but are not intended to limit this application. The terms“include” and “contain” and any variations thereof used in thespecification, claims, and brief description of drawings of thisapplication are intended as non-exclusive inclusion. The terms such as“first” and “second” used in the specification, claims, and briefdescription of drawings herein are intended to distinguish betweendifferent items, but are not intended to describe a specific sequence ororder of precedence.

Reference to “embodiment” in this application means that a specificfeature, structure or characteristic described with reference to theembodiment may be included in at least one embodiment of thisapplication. Reference to this term in different places in thespecification does not necessarily represent the same embodiment, nordoes it represent an independent or alternative embodiment in a mutuallyexclusive relationship with other embodiments. A person skilled in theart explicitly and implicitly understands that the embodiments describedin this application may be combined with other embodiments.

In the description of this application, unless otherwise expresslyspecified and defined, the terms “mount”, “concatenate”, “connect”, and“attach” are understood in a broad sense. For example, a “connection”may be a fixed connection, a detachable connection, or an integratedconnection; or may be a direct connection or an indirect connectionimplemented through an intermediary; or may be internal communicationbetween two components. A person of ordinary skill in the artunderstands the specific meanings of the terms in this applicationaccording to the context.

The term “and/or” in this application indicates merely a relation fordescribing the related items, and represents three possiblerelationships. For example, “A and/or B” may represent the followingthree circumstances: A alone, both A and B, and B alone. In addition,the character “/” herein generally indicates an “or” relationshipbetween the item preceding the character and the item following thecharacter.

“A plurality of” referred to in this application means two or more(including two). Similarly, “a plurality of groups” means two or moregroups (including two groups), and “a plurality of pieces” means two ormore pieces (including two pieces).

In this application, a battery cell may include a lithium-ion secondarybattery, a lithium-ion primary battery, a lithium-sulfur battery, asodium-lithium-ion battery, a sodium-ion battery, a magnesium-ionbattery, or the like, without being limited in embodiments of thisapplication. The battery cell may be in a cylindrical shape, a flatshape, a cuboidal shape, or other shapes, without being limited inembodiments of this application. Depending on the form of packaging, thebattery cell is typically classed into three types: cylindrical batterycell, prismatic battery cell, and pouch-type battery cell, without beinglimited in embodiments of this application.

Currently, with the progress of technology, power batteries are appliedmore widely. Power batteries are not only used in energy storage powersystems such as hydro, thermal, wind, and solar power stations, but alsowidely used in electric means of transport such as electric bicycles,electric motorcycles, and electric vehicles, and used in many otherfields such as military equipment and aerospace. The market demand forpower batteries keeps expanding with the widening of the fields to whichthe power batteries are applicable.

The inventor of this application has noticed that ions are intercalatedinto or deintercalated from a positive active material and a negativeactive material during charge-and-discharge cycles of a battery,resulting in expansion inside a cell core. An electrolytic solutioninside the cell core decreases gradually, resulting in electrolyteshortage inside the cell core and lack of active lithium components.With the aging of the cell core and excessive amount of gassing insidethe cell core, the problem of metal dissolution gradually occurs. Inseverer cases, thermal runaway may occur, and the battery is prone tofire or explosion. The resulting safety problems are nonnegligible.

In view of this, an electrolyte refilling mechanism is usually arrangedin a battery cell. The electrolyte refilling mechanism contains anelectrolytic solution. When expansion occurs inside the cell core and aninternal pressure increases, the electrolyte refilling mechanismruptures, and releases and provides pre-stored electrolytic solution tothe cell core, so as to make up for the electrolytic solution that islacking due to the increased charge-and-discharge cycles or aging of thecell core.

However, during research, the inventor of this application finds thatthe amount of the electrolytic solution that is lacking varies dependingon how long the cell core has been used. For example, after the cellcore has just been used for a short duration, just a small amount ofelectrolytic solution is lacking. With the increase of the duration ofbeing used, the amount of electrolytic solution that is lackingincreases gradually. Therefore, the cell core at different stages needsto be refilled with different dosages of electrolytic solution. Inaddition, the electrolyte shortage inside the cell core leads todifferent hazards in different stages of the cell core. Electrolyterefilling alone is unable to solve the problems arising in the long-termuse of the cell core. Currently, no solutions are available topertinently refilling the battery cell with the substance that islacking, and to resolving hazards at different stages. Refined solutionsare lacking.

In view of the foregoing factors, in order to solve the problems ofshortage of substances inside the cell core caused by excessivecharge-and-discharge cycles and aging of the cell core in use, theinventor of this application has carried out in-depth research anddesigned a novel tank, battery cell, and electrical device. A pluralityof independent accommodation cavities are arranged inside the tank, andeach accommodation cavity includes fragile structures that differ inpackaging strength. Therefore, the same substance or differentsubstances in the cell core can be released gradually in view of apressure inside the cell core that is in use or in different agingstates. For the cell core at different stages, different dosages ofelectrolytic solution or different types of desired substances areprovided, thereby improving pertinency of substance refilling for thecell core, and solving a series of problems arising at different usestages of the cell core, for example, electrolyte shortage, lack ofactive lithium, a large amount of gas generated, dissolution oftransition metal, and thermal runaway.

The tank and the battery cell disclosed in embodiments of thisapplication are applicable to, but without being limited to, electricaldevices such as a vehicle, watercraft, or aircraft. A power supplysystem of the electrical device may include the tank, the battery cell,and the like disclosed in this application to help alleviate theproblems such as lack of substances and degradation of safety of thecell core in use, and improve performance stability and longevity of thebattery.

An embodiment of this application provides an electrical device poweredby a battery. The electrical device may be, but without being limitedto, a mobile phone, a tablet, a notebook computer, an electric toy, anelectric tool, an electric power cart, an electric vehicle, a ship, aspacecraft, and the like. The electric toy may include stationary ormobile electric toys, such as a game console, an electric car toy, anelectric ship toy, an electric airplane toy, and the like. Thespacecraft may include an airplane, a rocket, a space shuttle, aspaceship, and the like.

For ease of description in the following embodiments, a vehicle 1000 isused as an example of the electrical device according to an embodimentof this application.

Referring to FIG. 1 , FIG. 1 is a schematic structural diagram of avehicle 1000 according to an embodiment of this application. The vehicle1000 may be an oil-fueled vehicle, a natural gas vehicle, or a newenergy vehicle. The new energy vehicle may be a battery electricvehicle, a hybrid electric vehicle, a range-extended electric vehicle,or the like. A battery 100 is disposed inside the vehicle 1000. Thebattery 100 may be disposed at the bottom, front, or rear of the vehicle1000. The battery 100 may be configured to supply power to the vehicle1000. For example, the battery 100 may serve as an operating powersupply of the vehicle 1000. The vehicle 1000 may further include acontroller 200 and a motor 300. The controller 200 is configured tocontrol the battery 100 to supply power to the motor 300, for example,to start or navigate the vehicle 1000, or meet the operating powerrequirements of the vehicle in operation.

In some embodiments of this application, the battery 100 serves not onlyas an operating power supply of the vehicle 1000, but may also serve asa drive power supply of the vehicle 1000 to provide driving power forthe vehicle 1000 in place of or partially in place of oil or naturalgas.

Referring to FIG. 2 , FIG. 2 is an exploded view of a battery 100according to an embodiment of this application. The battery 100 includesa box 10 and a battery cell 20. The battery cell 20 is accommodated inthe box 10. The box 10 is configured to provide an accommodation spacefor the battery cell 20. The box 10 may be variously structured. In someembodiments, the box 10 may include an upper box 11 and a lower box 12.The upper box 11 and the lower box 12 fit and cover each other. Theupper box 11 and the lower box 12 together define an accommodation spaceconfigured to accommodate the battery cell 20. The lower box 12 may be ahollow structure opened at one end. The upper box 11 may be a plate-likestructure. The upper box 11 fits an opening end of the lower box 12 sothat the upper box 11 and the lower box 12 together define theaccommodation space. Alternatively, both the upper box 11 and the lowerbox 12 may be hollow structures opened at one end. The opening end ofthe upper box 11 fits the opening end of the lower box 12. Definitely,the box 10 formed by the upper box 11 and the lower box 12 may be invarious shapes, such as a cylinder or a cuboid.

The battery 100 referred to in this embodiment of this application meansa stand-alone physical module that includes one or more battery cells toprovide a higher voltage and a higher capacity. For example, the battery100 referred to in this application may include a battery module, abattery pack, and the like. There may be a plurality of battery cells20, and the plurality of battery cells 20 may be connected in series,parallel, or series-and-parallel pattern. The series-and-parallelpattern means a combination of series connection and parallel connectionof the plurality of battery cells 20. The plurality of battery cells 20may be directly connected in series, parallel, or series-and-parallelpattern, and then the whole of the plurality of battery cells 20 may beaccommodated in the box 10. Alternatively, the plurality of batterycells 20 may be connected in series, parallel, or series-and-parallelpattern to form a battery 100 in the form of battery modules first. Aplurality of battery modules are then connected in series, parallel, orseries-and-parallel pattern to form a whole for being accommodated inthe box 10. The battery 100 may further include other structures. Forexample, the battery 100 may further include a busbar component. Thebusbar component is configured to implement electrical connectionbetween the plurality of battery cells 20.

Each battery cell 20 may be, but is not limited to, a lithium-ionsecondary battery, a lithium-ion primary battery, a lithium-sulfurbattery, a sodium-lithium-ion battery, or a magnesium-ion battery. Thebattery cell 20 may be in a cylindrical shape, a flat shape, a cuboidalshape, or other shapes.

For further understanding of the tank and the battery cell according toembodiments of this application, refer to a battery cell 20 shown inFIG. 3 . The battery cell 20 includes a housing 210, electrodes 220, anda cell core 240. The cell core 240 is located in the housing 210, and isconnected to the electrodes 220 and configured to output electricalenergy outward.

The housing 210 is a component configured to form an internalenvironment of the battery cell. The formed internal environment may beused to accommodate the cell core, an electrolytic solution, and othercomponents. The electrodes 220 are led out of the housing 210. Theelectrodes include a positive electrode and a negative electrode. Thepositive electrode and the negative electrode are connected to apositive tab and a negative tab of the cell core respectively by anadapter. The housing may be shaped and sized variously, for example,cuboidal, cylindrical, or hexagonal prismatic. Specifically, the shapeof the housing may be determined depending on the specific shape andsize of a cell core. The housing may be made of a variety of materialssuch as copper, iron, aluminum, stainless steel, aluminum alloy, orplastic, without being particularly limited herein.

In addition, when the battery cell is in use, gas is generated insidethe cell core over time. The gas pressure inside the housing increasesgradually. To ensure safety of the battery cell, an explosion-proofvalve 230 is arranged between electrodes on the housing. When the gaspressure in the battery cell reaches a given value, the pressure can bereleased through the explosion-proof valve to avoid safety problems suchas explosion of the battery cell.

The cell core 240 is a component that reacts electrochemically in thebattery cell 20. The housing may contain one or more cell cores. Thecell core is primarily formed by winding or stacking a positiveelectrode plate and a negative electrode plate, and a separator isgenerally arranged between the positive electrode plate and the negativeelectrode plate. The parts, coated with an active material, of thepositive electrode plate and the negative electrode plate, constitute abody portion of the cell core. The parts, coated with no activematerial, of the positive electrode plate and the negative electrodeplate, constitutes a positive tab and a negative tab, respectively. Thepositive tab and the negative tab may be located at one end of the bodyportion together or at two ends of the body portion respectively. In acharge-and-discharge process of the battery, the positive activematerial and the negative active material react with an electrolyticsolution. The tabs are connected to electrode terminals to form acurrent circuit. The positive tab is connected to the positive electrodeon the housing by an adapter, and the negative tab is connected to thenegative electrode on the housing by an adapter.

In order to refill the cell core with desired substances during the useof the battery cell, one or more tanks 40 are arranged between the cellcore 240 and the housing 210. The tanks 40 contain rapidly consumedsubstances such as electrolytic solution of the cell core. When the gaspressure in the battery cell or an expansion force of the cell corereaches a given value, the pressure acts on the tanks to crush thetanks, thereby releasing the electrolytic solution out of the tanks tosupplement the electrolytic solution of the cell core, therebyalleviating the problems such as performance deterioration caused byelectrolyte shortage after long-term use of the battery.

To solve the foregoing problems in the related art, the tank accordingto this embodiment of this application is applied to the foregoingbattery cell. The tank according to this application can release thesame substance or different substances gradually in view of a pressureinside the cell core that is in use or in different aging states. Forthe cell core at different stages, different dosages of electrolyticsolution or different types of desired substances are provided, therebysolving the problems such as lack of substances and deterioration ofsafety performance of the battery cell in use.

Specifically, the tank according to this embodiment of this applicationis shown in FIG. 4 to FIG. 7 . A plurality of independent accommodationcavities are arranged in the tank according to this embodiment of thisapplication. Each of the accommodation cavities includes a correspondingfragile structure. Each fragile structure possesses a differentpackaging strength.

In this embodiment of this application, the tank is usually acapsule-shaped or otherwise shaped object made of a flexible materialand capable of accommodating and storing liquid, inert gas, or otherforms of substances. Understandably, the tank is not necessarilycapsule-shaped, but may be made in any shape that meets requirements ofthe application environment, for example, may be square, round, oval, orirregularly shaped. The flexible material may be formed by stamping analuminum sheet and then sputtering an inert material onto the surface ofthe stamped aluminum sheet, where the inert material is a high-molecularpolymer such as PP, PE, PET, or PVC. Alternatively, the tank may be madeof other materials of specified flexibility and hardness.

A plurality of independent accommodation cavities may be arranged in thetank in the way shown in FIG. 4 or FIG. 6 . Identical or different tankmaterials may be used to partition the interior space of the tank into aplurality of independent closed spaces. The closed spaces formindependent accommodation cavities. The accommodation cavities areconfigured to hold liquid or inert gas. With the independentaccommodation cavities arranged, different liquids or inert gases can beseparated from each other, so as to release different substancespertinently.

Each accommodation cavity is formed by being surrounded by the flexiblematerial. A fragile structure is arranged on an outer wall of eachaccommodation cavity enclosed with the corresponding flexible material.That is, each accommodation cavity formed in the tank corresponds to afragile structure separately. In this way, the liquid or inert gasstored in each accommodation cavity can be released through thecorresponding fragile structure without affecting the filling substancestored in other accommodation cavities.

To release the filling substances from different accommodation cavitiesstepwise, this application assigns a different packaging strength to thefragile structure corresponding to each different accommodation cavity.In this way, among the corresponding fragile structures of theaccommodation cavities under the action of the internal pressure of thebattery cell, the filling substance in the accommodation cavitycorresponding to the fragile structure with the lowest packagingstrength is released first. The filling substances in the accommodationcavities corresponding to the fragile structures with relatively highpackaging strengths are released stepwise when the gas pressure in thebattery cell increases gradually. The packaging strength of the fragilestructure may be formed by making a fragile region in a given part ofthe flexible material in a way such as reducing the thickness of thegiven part by laser etching, acid etching of aluminum, or die-cut moldscratching of aluminum. The proportion of the fragile region in the areaof the entire outer wall of the tank is approximately 10% to 50%. Thethickness of the fragile region is generally 10 μm to 300 μm. Thepressure borne by the fragile region is less than that borne by othernon-thinned regions. The thickness may differ between the fragileregions depending on the required packaging strength. The pressurethreshold borne by the fragile region is positively correlated with thethickness (for example, the internal pressure threshold is 0.25 MPa whenthe thickness of the fragile region is 100 and the internal pressurethreshold is 0.4 MPa when the thickness is 200 μm). Therefore, eachcapsule can regulate the pressure relief order by using stepwisethicknesses of the fragile regions. Alternatively, the fragile regionsmay be formed by nicking a given part of the outer wall of the tank. Thedepth of the nick represents the packaging strength of the fragileregion. A great depth represents a lower packaging strength, and a smalldepth represents a higher packaging strength.

In this embodiment of this application, a plurality of independentaccommodation cavities are arranged inside the tank, each accommodationcavity includes a corresponding fragile structure, and each fragilestructure possesses a different packaging strength. In this way, thisembodiment implements the function of storing different types of fillingsubstances by using a single tank. The different filling substancesstored in the accommodation cavities in the tank can be releasedstepwise in response to different external pressures. Therefore, thecell core at different stages can be refilled with different dosages ofelectrolytic solution or different types of desired substances dependingon the internal pressure of the battery cell, thereby improvingpertinency of refilling the cell core with the desired substances.

To describe the structure of the tank in more detail, FIG. 4 shows aparent-child tank structure. One or more sub-tanks are arranged insidethe tank. The tank and the sub-tanks are nested with each other to formindependent accommodation cavities. Packaging strengths of thecorresponding fragile structures of the accommodation cavities increaseprogressively from outward to inward. FIG. 5 shows effects after theparent-child tank structure is filled with different substances.

As shown in FIG. 4 and FIG. 5 , the parent-child tank structure 50includes a first accommodation cavity 510, a second accommodation cavity520, and a third accommodation cavity 530. The first accommodationcavity 510 is formed by being enclosed with a first tank wall 511 and afirst fragile structure 512. A sub-tank is arranged inside the firstaccommodation cavity 510. The sub-tank includes a second accommodationcavity 520. The second accommodation cavity 520 is formed by beingenclosed with a second tank wall 521 and a second fragile structure 522.A sub-tank is further arranged inside the second accommodation cavity520. The sub-tank includes a third accommodation cavity 530. The thirdaccommodation cavity 530 is formed by being enclosed with a third tankwall 531 and a third fragile structure 532. As can be seen from FIG. 4 ,the outermost tank forms a parent tank of the parent-child tankstructure, and two sub-tanks are formed inside the parent tank. In otherwords, the tank and the sub-tanks are nested with each other to formindependent accommodation cavities. Tanks are further nested inside atank to form hierarchical nesting.

During formation of the parent-child tank, the innermost sub-tank isformed first. After the third filling substance 533 is injected into thethird accommodation cavity 530, the third accommodation cavity is sealedby laser welding or other means. At the same time, the third fragilestructure 532 is formed on the third tank wall 531. Subsequently, thesub-tank is wrapped in a flexible material to form a parent tank of thesub-tank. The second accommodation cavity 520 is formed between thesub-tank and the parent tank. After the second filling substance 523 isinjected into the second accommodation cavity 520, the secondaccommodation cavity is sealed by laser welding or other means. At thesame time, the second fragile structure 522 is formed on the second tankwall 521. Finally, the second sub-tank is further wrapped in a flexiblematerial to form a parent tank of the second sub-tank. The firstaccommodation cavity 510 is formed between the sub-tank and the parenttank. After the first filling substance 513 is injected into the firstaccommodation cavity 510, the first accommodation cavity is sealed bylaser welding or other means. At the same time, the first fragilestructure 512 is formed on the first tank wall 511. It needs to be notedthat FIG. 4 merely shows a structure in which three independentaccommodation cavities are arranged inside the parent-child tank. Feweror more sub-tanks may be arranged as required, details of which areomitted here.

In the parent-child tank structure, the packaging strengths of thefragile structures increase progressively in order from outside toinside of the parent-child tank structure. The first fragile structure512 is located on the surface of an outermost tank, and possesses thelowest packaging strength, and ruptures first when receiving an internalpressure of the battery cell. The packaging strength of the secondfragile structure 522 is higher than the packaging strength of the firstfragile structure, and the packaging strength of the third fragilestructure 532 is the highest. Under the action of the internal pressureof the battery cell, the fragile structures of the parent-child tank areruptured in sequence from outside to inside to release the first fillingsubstance 513, the second filling substance 523, and the third fillingsubstance 533 in sequence.

As can be seen from the foregoing embodiment, the parent-child tankstructure is nested hierarchically. A plurality of independentaccommodation cavities are arranged, each accommodation cavity includesa corresponding fragile structure, and each fragile structure possessesa different packaging strength. In this way, this embodiment implementsthe function of storing different types of filling substances by using asingle tank. The different filling substances stored in theaccommodation cavities in the tank can be released stepwise in responseto different external pressures, thereby improving pertinency ofrefilling the cell core with the desired substances.

In another embodiment of this application, another twin tank structure60 is provided. As shown in FIG. 6 , a membrane is arranged in the twintank. The membrane is configured to partition the interior of the tankinto a plurality of independent accommodation cavities. The fragilestructure is arranged at a position located on a surface of the tank andcorresponding to each accommodation cavity. Each fragile structurepossesses a different packaging strength. FIG. 7 is a schematic diagramof the twin tank filled with different substances.

As shown in FIG. 6 , a first accommodation cavity 610, a secondaccommodation cavity 620, and a third accommodation cavity 630 arearranged in the twin tank 60. The first accommodation cavity 610 isisolated from the second accommodation cavity 620 by a first membrane614. The second accommodation cavity 620 is isolated from the thirdaccommodation cavity 630 by a second membrane 624, so that theaccommodation cavities are independent of each other. The firstaccommodation cavity 610 is formed by being enclosed with a first tankwall 611, a first fragile structure 612, and a first membrane 614. Thefirst tank wall 611 and the first fragile structure are located outsidethe twin tank 60, and exposed outside. The first membrane 614 is locatedinside the twin tank 60, and isolates the first accommodation cavity 610from the second accommodation cavity 620 to make the two accommodationcavities independent of each other. The first membrane 614 may be madeof the same material as the first tank wall, or made of a differentmaterial. The first fragile structure 612 is arranged on a tank wallcorresponding to the first accommodation cavity 610. When the firstfragile structure 612 is ruptured, the filling substance in the firstaccommodation cavity 610 is released.

The second accommodation cavity 620 is formed by being enclosed with asecond tank wall 621, a second fragile structure 622, the first membrane614, and a second membrane 624. The second tank wall 621 and the secondfragile structure 622 are located outside the twin tank 60, andintegrated with the tank outer wall corresponding to the firstaccommodation cavity. The second membrane 624 is located inside the twintank 60, and works together with the first membrane 614 to partition theinterior space of the twin tank 60 to form an independent secondaccommodation cavity 620. The second membrane 624 may be made of thesame material as the second tank wall, or made of a different material.The second fragile structure 622 is arranged on a tank wallcorresponding to the second accommodation cavity 620. When the secondfragile structure 622 is ruptured, the filling substance in the secondaccommodation cavity 620 is released.

The third accommodation cavity 630 is formed by being enclosed with athird tank wall 631, a third fragile structure 632, and the secondmembrane 624. The third tank wall 631 and the third fragile structure632 are located outside the twin tank, and connected to the tank outerwall corresponding to the second accommodation cavity 620. The secondmembrane 624 is located inside the twin tank 60, and partitions theinterior space of the twin tank 60 into a second accommodation cavity620 and a third accommodation cavity 630. The third fragile structure632 is arranged on a tank wall corresponding to the third accommodationcavity 630. When the third fragile structure 632 is ruptured, thefilling substance in the third accommodation cavity 630 is released.

In the twin tank shown in FIG. 6 , the first membrane 610 and the secondmembrane 620 are arranged to partition the interior space of the twintank 60 into three independent accommodation cavities. The threeindependent accommodation cavities correspond to separate fragilestructures respectively. The corresponding fragile structure of eachaccommodation cavity possesses a different packaging strength. Forexample, in FIG. 6 , the packaging strength of the first fragilestructure 612 is greater than the packaging strength of the secondfragile structure 622, and the packaging strength of the second fragilestructure 622 is greater than the packaging strength of the thirdfragile structure 632. In this way, among the corresponding fragilestructures of the accommodation cavities under the action of the gaspressure in the battery cell, the filling substance in the accommodationcavity corresponding to the fragile structure with the lowest packagingstrength is released first. The filling substances in the accommodationcavities corresponding to the fragile structures with relatively highpackaging strengths are released stepwise when the gas pressure in thebattery cell increases gradually. To be specific, the filling substancein the third accommodation cavity 630 is released first, the fillingsubstance in the second accommodation cavity 620 is released later, andthe filling substance in the first accommodation cavity 610 is releasedlast. The packaging strength of the fragile structure may be formed bymaking a fragile region in a given part of the flexible material in away such as reducing the thickness of the given part by laser etching,acid etching of aluminum, or die-cut mold scratching of aluminum. Theproportion of the fragile region in the area of the entire outer wall ofthe tank is approximately 10% to 50%. The thickness of the fragileregion is generally 10 μm to 300 μm. The pressure borne by the fragileregion is less than that borne by other non-thinned regions. Thethickness may differ between the fragile regions depending on therequired packaging strength. The pressure threshold borne by the fragileregion is positively correlated with the thickness (for example, theinternal pressure threshold is 0.25 MPa when the thickness of thefragile region is 100 μm, and the internal pressure threshold is 0.4 MPawhen the thickness is 200 μm). Therefore, each capsule can regulate thepressure relief order by using stepwise thicknesses of the fragileregions. The fragile regions may be arranged in various ways. Anotherway of forming the fragile regions is to nick a given part of the outerwall of the tank. The depth of the nick represents the packagingstrength of the fragile region. The packaging strength is lower if thedepth is great, and the packaging strength is higher if the depth issmall.

During formation of the twin tank 60, first, the first membrane 614 andthe second membrane 62 are arranged inside the tank wall by welding orgluing or other means. The first membrane 614, the second membrane 62,and the outer wall of the tank form an accommodation cavity. After thefilling substance is injected into each accommodation cavity, theaccommodation cavity is sealed by laser welding or other means, therebyforming a twin tank structure.

FIG. 7 is a schematic diagram of a twin tank 60 after independentaccommodation cavities in the twin tank are filled with fillingsubstances. The first accommodation cavity 610 is filled with a firstfilling substance 613, the second accommodation cavity 620 is filledwith a second filling substance 623, and the third accommodation cavity630 is filled with a third filling substance 633. The filling substancesmay be the same or different. When the filling substances are the same,the same substance can be released in an orderly manner under differentpressures in the battery cell. When the filling substances aredifferent, different substances can be released in an orderly mannerunder different pressures in the battery cell to refill the battery cellwith various desired substances.

Definitely, in order to increase the flexibility of using the twin tank,the packaging strengths of the fragile structures may be set atdiscretion. For example, when the number of independent accommodationcavities in the twin tank is relatively large, for example, is 5 to 9,the fragile structures corresponding to two or three accommodationcavities may be set to possess the same packaging strength, so as toincrease the dosage of a substance released at a time. Alternatively,the difference in the packaging strength between the fragile structuresmay be reduced, so as to reduce intervals at which differentaccommodation cavities release the filling substance, and to refill thecell core with the desired substance stepwise at dense intervals.Moreover, the capacity may be identical or different between theaccommodation cavities. The capacity of each accommodation cavity may beset at discretion according to the use characteristics of the cell core.The substance consumed by the cell core in a large amount may be storedin a large-capacity accommodation cavity, and the substance consumed ina small amount may be stored in a small-capacity accommodation cavity.Definitely, other arrangement manners are applicable, without beinglimited in this embodiment of this application. By adjusting thecapacity of the accommodation cavity and the packaging strength of thefragile structure at discretion, the battery cell can be refilled withdesired substances more efficiently.

As can be seen from the foregoing embodiment, in the twin tankstructure, the membrane partitions the interior space of the tank into aplurality of independent accommodation cavities. Each accommodationcavity includes a corresponding fragile structure, and each fragilestructure possesses a different packaging strength. In this way, thisembodiment implements the function of storing different types of fillingsubstances by using a single tank. The different filling substancesstored in the accommodation cavities in the tank can be releasedstepwise in response to different external pressures, thereby improvingpertinency of refilling the cell core with the desired substances.

An embodiment of this application further provides a battery cell. Asshown in FIG. 8 to FIG. 10 , the battery cell includes a housing 210, acell core 240, and the parent-child tank 50 and/or the twin tank 60disclosed in the foregoing embodiments. The cell core 240 isaccommodated in the housing 210. The parent-child tank 50 and/or thetwin tank 60 is accommodated in the housing, and arranged correspondingto a sidewall of the cell core 240.

As shown in FIG. 8 , the battery cell 20 includes one or moreparent-child tanks 50. The structures of the parent-child tanks 50 areillustrated in FIG. 4 and FIG. 5 , description of which is omitted here.In FIG. 8 , the parent-child tank is arranged corresponding to asidewall of the cell core 240. The sidewall of the cell core includes asidewall of the cell core in a height direction, a sidewall in a widthdirection, a sidewall of the cell core in a thickness direction, and thelike. As shown in FIG. 8 , the first parent-child tank 501 and thesecond parent-child tank 502 are arranged between a sidewall of the cellcore in the height direction and the housing. The parent-child tank maybe arranged on the housing by gluing or laser welding or other means, orarranged on the cell core. Alternatively, the parent-child tank may beplaced in all gaps between the sidewall and the housing, so as to fillall spaces. The third parent-child tank 503 is arranged corresponding toa sidewall of the cell core in the height direction, and located at thebottom of the housing of the battery cell. The fourth parent-child tank504 is arranged corresponding to a sidewall at the other end of the cellcore in the height direction, and located on the top of the cell core.When the parent-child tank is arranged on the top of the cell core inthe height direction, the substance released by the tank permeates intoan electrode core of the cell core more easily due to gravity, therebyimproving the effect of electrolyte refilling.

As shown in FIG. 9 , the battery cell 20 includes one or more twin tanks60. The structures of the twin tanks 60 are illustrated in FIG. 6 andFIG. 7 , description of which is omitted here. In FIG. 9 , the twin tankis arranged corresponding to a sidewall of the cell core 240. Thesidewall of the cell core includes a sidewall of the cell core in theheight direction, a sidewall in a width direction, a sidewall of thecell core in a thickness direction, and the like. Alternatively, thetwin tank may be arranged in any interspace inside the cell core,including any interspace on two sides of or above the cell core or otherspaces, without limiting the number and shape of the tanks.

As shown in FIG. 9 , the first twin tank 601 and the second twin tank602 are arranged between a sidewall of the cell core in the heightdirection and the housing. The twin tank may be arranged on the housingby gluing or laser welding or other means, or arranged on the cell core.Alternatively, the twin tank may be placed in all gaps between thesidewall and the housing, so as to fill all spaces. The third twin tank603 is arranged corresponding to a sidewall of the cell core in theheight direction, and located at the bottom of the housing of thebattery cell. The fourth twin tank 604 is arranged corresponding to asidewall on the top of the cell core in the height direction. When thetwin tank is arranged on the top of the cell core in the heightdirection, the substance released by the tank permeates into anelectrode core of the cell core more easily due to gravity, therebyimproving the effect of electrolyte refilling.

In this embodiment of this application, further, as shown in FIG. 10 ,the parent-child tank 50, the twin tank 60, and the discrete tank 40 maybe arranged compositely in the battery cell. As shown in FIG. 10 , adiscrete tank 40 and a parent-child tank 50 are arranged between asidewall at one end of the cell core in the height direction and thehousing 210, and a discrete tank 40 and a twin tank 60 are arrangedbetween a sidewall at the other end of the cell core in the heightdirection and the housing 210. The discrete tank 40 is a tank structurewith a single separate accommodation cavity. With only one accommodationcavity, a discrete tank can store a larger amount of a substance than atwin tank 60 or parent-child tank 50 of the same size. Therefore,arranging the discrete tank 40, the twin tank 60, and the parent-childtank 50 compositely can meet a requirement of supplementing a substancein large amounts. For example, during the use of the cell core, theelectrolytic solution is most consumed over time. Therefore, theelectrolytic solution may be stored in the discrete tank 40, and othersubstances may be stored in the twin tank 60 and the parent-child tank50. Such a combination diversifies the ways of refilling the cell corewith substances. As shown in FIG. 10 , with respect to the location ofthe tank, the tank may also be arranged on a sidewall of the cell core.The sidewall includes a sidewall of the cell core in a height direction,a sidewall in a width direction, a sidewall of the cell core in athickness direction, and the like.

By arranging the tank structure with a plurality of accommodationcavities in the battery cell, this embodiment implements the function ofstoring different types of filling substances by using a single tank.The different filling substances stored in the accommodation cavities inthe tank can be released stepwise in response to different externalpressures, thereby improving pertinency of refilling the cell core withthe desired substances. Moreover, with the twin tank and theparent-child tank arranged compositely inside the battery cell, the cellcore can be refilled with substances precisely and meticulously.

In some embodiments, as shown in FIG. 8 and FIG. 9 , in order to improvethe effect of infiltration, the fragile structure of the tank isarranged corresponding to the sidewall of the cell core. That is, thefragile structure fits closely with the outer wall of the cell core. Nomatter whether the structure is a discrete tank, a parent-child tank, ora twin tank, the filling substance stored in the accommodation cavity inthe tank overflows from the fragile structure. With the fragilestructure arranged corresponding to the sidewall of the cell core, thefilling substance can contact the sidewall of the cell core first,thereby improving the effect of infiltration. For the tank arranged atone end of the cell core in the height direction, the fragile structureclosely fits with a tab part of the cell core downward. When the fragilestructure is ruptured, the overflowing filling substance infiltrates theinterior of the cell core more easily due to gravity.

In some embodiments, as shown in FIG. 11 , the battery cell includes aplurality of cell cores. The tank is arranged between each cell core anda sidewall of the housing, and/or the tank is arranged between adjacentcell cores.

As shown in FIG. 11 , the battery cell 20 includes a plurality of cellcores. The discrete tank, the twin tank, and the parent-child tank arearranged compositely between the sidewall of the cell core and thehousing. At the same time, a tank structure is also arranged betweendifferent cell cores. To improve the effect of infiltration, a tankstructure is arranged between different cell cores. When the gaspressure in the battery cell is excessive, or the cell core expandsduring use, in a case that the expansion force is greater than apressure threshold tolerable by the fragile structure of the tank, thetank arranged between the cell cores is ruptured, and the overflowingsubstance directly contacts the cell core, so that the cell core canabsorb the desired substance more efficiently.

For the tank structure arranged between cell cores, in order to improvethe effect of infiltration, the tank includes a plurality of fragilestructures. The plurality of fragile structures are arrangedcorresponding to the sidewalls of the cell core respectively, as shownin FIG. 12 and FIG. 13 . FIG. 12 shows a parent-child tank structure.The parent-child tank includes a plurality of independent accommodationcavities. At least two fragile structures are arranged on a tank wallcorresponding to each of the accommodation cavities. In FIG. 12 , thetank wall corresponding to the accommodation cavity 510 includes twofirst fragile structures 512 and 515, located on two sides of the tankrespectively. The two fragile structures are arranged corresponding tothe sidewalls of the cell core on two sides respectively. Similarly, thesub-tank corresponding to the accommodation cavity 520 also includes twosecond fragile structures 522 and 525. After a second fragile structureis ruptured, when the pressure in the battery cell reaches a pressurethreshold of the first fragile structure, the fragile structures on twosides of the sub-tank are ruptured simultaneously, and the fillingsubstance overflows from both sides. Both sides of the cell core cancontact the overflowing filling substance, thereby improving the effectof infiltration. Similarly, the sub-tank corresponding to theaccommodation cavity 530 also includes two third fragile structures 532and 535. When the pressure in the battery cell reaches a threshold, thethird fragile structures are cracked at the same time, thereby improvingthe effect of infiltration.

FIG. 13 shows a twin tank structure. The twin tank includes a pluralityof independent accommodation cavities. At least two fragile structuresare arranged on a tank wall corresponding to each of the accommodationcavities. In FIG. 13 , the accommodation cavity 610 includes two firstfragile structures 612 and 615, located on two sides of the tankrespectively. The two fragile structures are arranged corresponding tothe sidewalls of the cell core on two sides respectively. Similarly, thetank corresponding to the accommodation cavity 620 also includes twosecond fragile structures 622 and 625. After a second fragile structureis ruptured, when the pressure in the battery cell reaches a pressurethreshold of the first fragile structure, the fragile structures on twosides of the tank are ruptured simultaneously, and the filling substanceoverflows from both sides. Both sides of the cell core can contact theoverflowing filling substance, thereby improving the effect ofinfiltration. Similarly, the tank corresponding to the accommodationcavity 630 also includes two third fragile structures 632 and 635.

By arranging a plurality of fragile structures on the tank wallcorresponding to the accommodation cavity, and by arranging a pluralityof fragile structures corresponding to the sidewalls of the cell corerespectively, the tank can release the filling substance from theplurality of fragile structures simultaneously. A plurality of parts ofthe cell core can contact the filling substance simultaneously, therebyimproving the effect of infiltration for the cell core, and making thecell core absorb the desired filling substance more efficiently.

In some embodiments, an explosion-proof valve is arranged on the housing210 of the battery cell 20, and the tank is arranged opposite to theexplosion-proof valve 230. As shown in FIG. 8 to FIG. 11 , anexplosion-proof valve 230 is arranged between electrodes 220 on thehousing of the battery cell. The explosion-proof valve 230 is a pressurerelief hole designed to prevent an excessive gas pressure inside thebattery cell. When the gas pressure in the battery cell is higher than agiven threshold, the gas in the battery cell is released through theexplosion-proof valve, thereby relieving the gas pressure in the batterycell. By arranging the tank opposite to the explosion-proof valve, thefilling substance stored in the tank can be released more efficiently.

In some embodiments, each fragile structure of the tank possesses adifferent packaging thickness. To release the filling substances fromdifferent accommodation cavities stepwise, this application assigns adifferent packaging strength to the fragile structure corresponding toeach different accommodation cavity. In this way, among thecorresponding fragile structures of the accommodation cavities under theaction of the internal pressure of the battery cell, the fillingsubstance in the accommodation cavity corresponding to the fragilestructure with the lowest packaging strength is released first. Thefilling substances in the accommodation cavities corresponding to thefragile structures with relatively high packaging strengths are releasedstepwise when the gas pressure in the battery cell increases gradually.The packaging strength of the fragile structure may be formed by makinga fragile region in a given part of the flexible material in a way suchas reducing the thickness of the given part by laser etching, acidetching of aluminum, or die-cut mold scratching of aluminum. Theproportion of the fragile region in the area of the entire outer wall ofthe tank is approximately 10% to 50%. The thickness of the fragileregion is generally 10 μm to 300 μm. The pressure borne by the fragileregion is less than that borne by other non-thinned regions. Thethickness may differ between the fragile regions depending on therequired packaging strength. The pressure threshold borne by the fragileregion is positively correlated with the thickness (for example, theinternal pressure threshold is 0.25 MPa when the thickness of thefragile region is 100 and the internal pressure threshold is 0.4 MPawhen the thickness is 200 μm). Therefore, each capsule can regulate thepressure relief order by using stepwise thicknesses of the fragileregions. The fragile regions may be arranged in various ways. Anotherway of forming the fragile regions is to nick a given part of the outerwall of the tank. The depth of the nick represents the packagingstrength of the fragile region. The packaging strength is lower if thedepth is great, and the packaging strength is higher if the depth issmall.

In some embodiments, the packaging strengths of the fragile structureschange stepwise. In order to adapt to the pressure in the battery celland release the filling substances in the accommodation cavities in thetank stepwise in batches, in view of the characteristics of the internalpressure of the cell core and the substances required by the cell corein different pressure stages, this application arranges the packagingstrengths of the corresponding fragile structures of the accommodationcavities to change stepwise, so as to gradually release the substancesrequired by the cell core.

In some embodiments, each accommodation cavity stores a differentsubstance. As described in the foregoing embodiments, the accommodationcavities may store different substances according to the substancesrequired by the cell core at different stages, for example, may storelithium supplementing agent, flame retardant, electrolytic solution,component/gas absorbent, metal capturing agent, and the like. Therelease of stored substances achieves the purposes of improvinglongevity and safety of the cell core.

Definitely, the accommodation cavities of the tank may store the samesubstance, such as electrolytic solution. The electrolytic solution issufficient in an early stage of the lifecycle of the battery. When theaging of the battery aggravates and the electrolytic solution keepsbeing consumed over time, side reaction products gradually accumulateand the internal gas pressure keeps rising. The corresponding fragileregions are ruptured stepwise in ascending order of thickness of thefragile regions when the internal pressure keeps increasing (that is,when the aging keeps aggravating). The regions release the electrolyticsolution in sequence, thereby overcoming a cycle capacity plunge causedby lithium plating arising from insufficient electrolyte circulation.

In some embodiments of this application, the accommodation cavitiesstore a flame retardant, a gas absorbent, a lithium supplementing agent,and an electrolytic solution respectively in descending order of thepackaging strength of the fragile structure. Problems such as lack ofelectrolytic solution and lithium ions usually occur over time when thecell core is in use. At a later stage, the problems such as increasedamount of gas generated in the battery and increased fire hazards aremore prone to occur. In this embodiment of this application, theforegoing hazards are resolved in a pertinent manner. The cell core isrefilled with the electrolytic solution, lithium supplementing agent,gas absorbent, and flame retardant separately.

In a case that the electrolytic solution is severely consumed at themiddle and later stages of the lifecycle, the electrolytic solution issupplemented in time to enhance the effect of infiltration for electrodeplates, avoid central lithium plating caused by insufficient electrolytecirculation, and improve an end-of-line test (EOL) capacity retentionrate and longevity, power performance, fast charge capability, and thelike. Therefore, the electrolytic solution and lithium ions need to besupplemented in large amounts. In addition, the amount of gas generatedin the cell core in use increases significantly over time. In this case,the tanks can release a gas hardener/absorbent (such as CaO) to hardenand absorb the gas (CO₂) in the cell core, thereby achieving the effectsof EOL degassing and internal pressure relief, and reducing the risk ofthe explosion-proof valve bursting open. At the later stage of thelifetime of the cell core, when lithium dendrites pierce a separator orthermal runaway ultimately occurs in an abuse test due to defects of thecell core at the end of life, the pressure surges up instantaneously andreaches a packaging strength threshold of the fragile structure thatpossesses the maximum packaging strength. In this case, the flameretardant needs to be released to implement rapid cooling, control theseverity of thermal runaway, and improve safety performance.

In some embodiments, another battery cell 20 is provided. As shown inFIG. 14 , the battery cell includes a housing 210, a cell core 240, anda plurality of tanks. The cell core is accommodated in the housing. Theplurality of tanks are accommodated in the housing, and arrangedcorresponding to sidewalls of the cell core respectively. A fragilestructure is arranged on a surface of each of the tanks, and the fragilestructure of each tank possesses a different packaging strength.

As shown in FIG. 15 , the tank is a discrete tank 40. The discrete tank40 includes an accommodation cavity 410. The accommodation cavity 410 isformed by being enclosed with a tank wall 411 and a fragile structure412. As mentioned in the foregoing embodiment, the packaging strength ofthe fragile structure 412 may be formed by making a fragile region in agiven part of the flexible material in a way such as reducing thethickness of the given part by laser etching, acid etching of aluminum,or die-cut mold scratching of aluminum. The proportion of the fragileregion in the area of the entire outer wall of the tank is approximately10% to 50%. The thickness of the fragile region is generally 10 μm to300 μm. The pressure borne by the fragile region is less than that borneby other non-thinned regions. The thickness may differ between thefragile regions depending on the required packaging strength. Thepressure threshold borne by the fragile region is positively correlatedwith the thickness (for example, the internal pressure threshold is 0.25MPa when the thickness of the fragile region is 100 and the internalpressure threshold is 0.4 MPa when the thickness is 200 μm). Therefore,each capsule can regulate the pressure relief order by using stepwisethicknesses of the fragile regions. The fragile regions may be arrangedin various ways. Another way of forming the fragile regions is to nick agiven part of the outer wall of the tank. As shown in FIG. 16 , afragile region 413 is formed by nicking. The depth of the nickrepresents the packaging strength of the fragile region. A great depthrepresents a lower packaging strength, and a small depth represents ahigher packaging strength.

A plurality of discrete tanks with different fragile structures arearranged inside the battery cell. As shown in FIG. 14 , the discretetanks include a first discrete tank 401, a second discrete tank 402, athird discrete tank 403, a fourth discrete tank 404, and the like. Aplurality of discrete tanks are accommodated in the housing, and arearranged corresponding to sidewalls of the cell core respectively. Thefirst discrete tank 401 includes a first tank wall 411 and a firstfragile structure 412. The second discrete tank 402 includes a secondtank wall 421 and a second fragile structure 422. The first fragilestructure and the second fragile structure possess different packagingstrengths. Similarly, the third discrete tank, the fourth discrete tank,and the like, include fragile structures that possess differentpackaging strengths. A plurality of discrete tanks with fragilestructures of different packaging strengths are arranged in the batterycell, so that different discrete tanks can release different fillingsubstances stepwise in sequence under different pressures.

In some embodiments, in order to improve the effect of infiltration, thefragile structure of the tank is arranged corresponding to the sidewallof the cell core. That is, the fragile structure fits closely with theouter wall of the cell core. No matter whether the structure is adiscrete tank, a parent-child tank, or a twin tank, the fillingsubstance stored in the accommodation cavity in the tank overflows fromthe fragile structure. With the fragile structure arranged correspondingto the sidewall of the cell core, the filling substance can contact thesidewall of the cell core first, thereby improving the effect ofinfiltration. For the tank arranged at one end of the cell core in theheight direction, the fragile structure closely fits with a tab part ofthe cell core downward. When the fragile structure is ruptured, theoverflowing filling substance infiltrates the interior of the cell coremore easily.

In some embodiments, the battery cell includes a plurality of cellcores. The tank is arranged between each cell core and a sidewall of thehousing, and/or the tank is arranged between adjacent cell cores.

As shown in FIG. 11 , the battery cell 20 includes a plurality of cellcores. Between the cell cores, the twin tank and the parent-child tankin FIG. 11 may be replaced with discrete tanks, details of which areomitted here. To improve the effect of infiltration, a tank structure isarranged between different cell cores. When the gas pressure in thebattery cell is excessive, or the cell core expands during use, in acase that the expansion force is greater than a pressure thresholdtolerable by the fragile structure of the tank, the tank arrangedbetween the cell cores is ruptured, and the overflowing substancedirectly contacts the cell core, so that the cell core can absorb thedesired substance more efficiently.

For the discrete tank structure arranged between cell cores, in order toimprove the effect of infiltration, a plurality of fragile structuresare arranged on the wall of the discrete tank. The plurality of fragilestructures are arranged corresponding to the sidewalls of the cell corerespectively, as shown in FIG. 17 . FIG. 17 shows a discrete tankstructure. The discrete tank includes first fragile structures 412 and414. When the pressure in the battery cell reaches a pressure thresholdof the first fragile structure, the fragile structures on two sides ofthe discrete tank are ruptured simultaneously, and the filling substanceoverflows from both sides. Both sides of the cell core can contact theoverflowing filling substance, thereby improving the effect ofinfiltration.

In some embodiments, each fragile structure of the tank possesses adifferent packaging thickness. The packaging strength of the fragilestructure may be formed by making a fragile region in a given part ofthe flexible material in a way such as reducing the thickness of thegiven part by laser etching, acid etching of aluminum, or die-cut moldscratching of aluminum. The proportion of the fragile region in the areaof the entire outer wall of the tank is approximately 10% to 50%. Thethickness of the fragile region is generally 10 μm to 300 μm. Thepressure borne by the fragile region is less than that borne by othernon-thinned regions. The thickness may differ between the fragileregions depending on the required packaging strength.

In some embodiments, the packaging strengths of the fragile structureschange stepwise. In order to adapt to the gas pressure in the batterycell and release the filling substances in the tanks stepwise inbatches, in view of the characteristics of the internal pressure of thecell core and the substances required by the cell core in differentpressure stages, this application sets the packaging strengths of thefragile structures corresponding to the tanks in such a way that thepackaging strengths change stepwise to gradually release the substancesrequired by the cell core.

According to some embodiments of this application, a battery is furtherdisclosed. The battery includes any one of the battery cells mentionedin the foregoing embodiments. The battery cell may include one or moreparent-child tanks, or one or more twin tanks, or a plurality ofdiscrete tanks, or may include a combination of parent-child tanks, twintanks, and discrete tanks. Each tank may store one or more substancesrequired by the cell core. Therefore, the same substance or differentsubstances in the cell core can be released gradually in view of apressure inside the cell core that is in use or in different agingstates. For the cell core at different stages, different dosages ofelectrolytic solution or different types of desired substances areprovided, thereby improving pertinency of refilling the cell core withsubstances.

According to some embodiments of this application, an electrical deviceis further provided. The electrical device includes the batterydisclosed in the foregoing embodiment, and the battery is configured toprovide electrical energy for the electrical device. The electricaldevice may be, but without being limited to, a mobile phone, a tablet, anotebook computer, an electric toy, an electric tool, an electric powercart, an electric vehicle, a ship, a spacecraft, and the like. Theelectric toy may include stationary or mobile electric toys, such as agame console, an electric car toy, an electric ship toy, an electricairplane toy, and the like. The spacecraft may include an airplane, arocket, a space shuttle, a spaceship, and the like.

Finally, it needs to be noted that the foregoing embodiments are merelyintended to describe the technical solutions of this application, butnot to limit this application. Although this application is described indetail with reference to the foregoing embodiments, a person of ordinaryskill in the art understands that modifications may still be made to thetechnical solutions described in the foregoing embodiments or equivalentreplacements may still be made to some technical features thereof,without making the essence of the corresponding technical solutionsdepart from the spirit and scope of the technical solutions of theembodiments of this application.

What is claimed is:
 1. A tank, comprising: a plurality of independentaccommodation cavities, each of the accommodation cavities comprising acorresponding fragile structure, and the fragile structures possessingdifferent packaging strengths.
 2. The tank according to claim 1,comprising: a tank wall; and one or more sub-tanks inside the tank;wherein: the tank wall and the sub-tanks are nested with each other toform the independent accommodation cavities; and the packaging strengthsof the corresponding fragile structures of the accommodation cavitiesincrease progressively from outward to inward.
 3. The tank according toclaim 1, comprising: a membrane arranged in the tank, the membrane beingconfigured to partition an interior of the tank into a plurality ofindependent accommodation cavities; and the fragile structures arearranged at position on a surface of the tank and corresponding to theaccommodation cavities, respectively.
 4. A battery cell, comprising: ahousing; a cell core, accommodated in the housing; and a tank,accommodated in the housing and arranged corresponding to a sidewall ofthe cell core, the tank comprising: a plurality of independentaccommodation cavities, each of the accommodation cavities comprising acorresponding fragile structure, and the fragile structures possessingdifferent packaging strengths.
 5. The battery cell according to claim 4,wherein the fragile structure of each of the accommodation cavities isarranged corresponding to the sidewall of the cell core.
 6. The batterycell according to claim 4, wherein: the cell core is one of a pluralityof cell cores accommodated in the housing; and the tank is arrangedbetween one of the cell cores and a sidewall of the housing, and/or thetank is arranged between adjacent ones of the cell cores.
 7. The batterycell according to claim 6, wherein the plurality of fragile structuresare arranged corresponding to sidewalls of the cell core, respectively.8. The battery cell according to claim 4, further comprising: anexplosion-proof valve arranged on the housing; wherein the tank isarranged opposite to the explosion-proof valve.
 9. The battery cellaccording to claim 4, wherein the fragile structure possess differentpackaging thicknesses.
 10. The battery cell according to claim 4,wherein the packaging strengths of the fragile structures changestepwise.
 11. The battery cell according to claim 4, wherein differentones of the accommodation cavities store different substances.
 12. Thebattery cell according to claim 11, wherein the accommodation cavitiesstore a flame retardant, a gas absorbent, a lithium supplementing agent,and an electrolytic solution, respectively, in descending order of thepackaging strengths of the corresponding fragile structures.
 13. Abattery cell, comprising: a housing; a cell core, accommodated in thehousing; and a plurality of tanks, accommodated in the housing and eacharranged corresponding to a sidewall of the cell core; wherein: afragile structure is arranged on a surface of each of the tanks; and thefragile structures of the tanks possess different packaging strengths.14. The battery cell according to claim 13, wherein the fragilestructure of each of the tanks is arranged corresponding to the sidewallof the cell core.
 15. The battery cell according to claim 13, wherein:the cell core is one of a plurality of cell cores accommodated in thehousing; and each of the tanks is arranged between one of the cell coresand a sidewall of the housing, and/or each of the tanks is arrangedbetween adjacent ones of the cell cores.
 16. The battery cell accordingto claim 15, wherein the plurality of fragile structures are arrangedcorresponding to sidewalls of the cell core, respectively.
 17. Thebattery cell according to claim 13, wherein the fragile structures ofthe tanks possess different packaging thicknesses.
 18. The battery cellaccording to claim 13, wherein the packaging strengths of the fragilestructures of the tanks change stepwise.
 19. A battery, comprising thebattery cell according to claim
 13. 20. An electrical device, comprisingthe battery according to claim 19, the battery being configured toprovide electrical energy.